while otherwise quite mysterious?

Does "The existence of psychopaths, while otherwise quite mysterious" mean "The existence of psychopaths, while other forms of existence/lifestyle are quite mysterious to them/psychopaths"?

Context:

Game theory suggests that evolution probably selected for two stable
orientations toward human cooperation: tit for tat (often called "strong
reciprocity" and permanent defection. Tit for tat is generally what we see throughout society: you show me some kindness, and I am eager to return the favor; you do something rude or injurious, and the temptation to respond in kind becomes difficult to resist. But consider how permanent defection would appear at the level of human relationships: the defector would probably engage in continuous cheating and manipulation, sham moralistic aggression (to provoke guilt and altruism in others), and strategic mimicry of positive social emotions like sympathy (as well as of negative emotions like guilt). This begins to sound like garden-variety psychopathy. The existence of psychopaths, while otherwise quite mysterious, would seem to be predicted by game theory. And yet, the psychopath who lives his entire life in a tiny village must be at a terrible disadvantage. The stability of permanent defection as a strategy would require that a defector be able to find people to fleece who are not yet aware of his terrible reputation. Needless to say, the growth of cities has made this way of life far more practicable than it has ever
been.

The Moral Landscape P68-69